We will be making a trip in October to the Stubai Glacier which includes driving an auto on the small village roads. Any advice on the normal weather conditions during early October will be greatly appreciated. Do autos need to be fitted with snow tires and carry chains or is this transitional period ok to traverse with normal tires in Stubaital?
winter rules begin 1st November.
Occasional snow may be possible in early October - as can almost summer weather with fairly high temperatures. Rain can happen at any moment pretty much all year..
You should probably have winter tires. Mine go on in October. Road maintenance is good for snow clearing. You might not see any snow in the valley at all. Small village roads are more like a main drags for skiers. I have not used snow chains in 25 years. There is always a chance of a freak storm, but nothing to worry about. I carry the winter chains in the bottom of the trunk. For a rental you can ask for an Allrad (4x4).
You have been given great advice. I will add one: if you need an automatic, book ASAP. I used gemut.com to book rental cars in Europe and they are fantastic.